Display systems for entertainment, architectural, and advertising purposes have commonly been constructed from arrays of light emitting elements such as light emitting diodes (LEDs) and incandescent lamps mounted onto or within flat panels. The light emitting elements can be selectively turned on and off to create patterns, graphics and video displays for both informational and aesthetic purposes. It is well known to construct these displays as tiles or large panels that are assembled in position for a specific entertainment show or event, or as an architectural or advertising display. Examples of such systems are disclosed in U.S. Pat. No. 6,813,853, U.S. Pat. No. 6,704,989, and U.S. Pat. No. 6,314,669. Such systems are typically heavy and time-consuming to install, and once in position are not easily altered. In addition, such systems are typically difficult to remove.
It is often necessary for a given event, theatrical production or architectural design to use such a display but to have the display easily removed. For example, it may be desirable to have the display removed between the scenes of a play or theatrical event or as the needs of the production otherwise dictate. In the case of an architectural installation, it may be desirable for the display to be visible at night, but removed or inconspicuous during the day. A display constructed as a large panel or as a series of large tiles can not easily be removed in this manner. Typically, as noted above, such displays are large and heavy and require significant support machinery, time, and storage space to move and install. For example, U.S. Pat. No. 6,704,989 discloses a system where individual display sections are lifted out of storage cases using a lifting truss, and are thereafter joined and stacked. Other prior art systems may use a tile-based structure wherein tiles, typically approximately 2 ft by 2 ft square, may be lifted by hand and installed manually. This is a time-consuming and complex process requiring the involvement of skilled personnel. Other prior art systems, such as the MiPIX system from Barco Media & Entertainment of Belgium use very small tiles that can be mounted within a framework. MiPIX tiles are small and easy to handle, but again are extremely time-consuming to install. Also, the resulting structure is heavy, unmanageable, and can not easily be removed.
It may be a further requirement for events, theatrical productions, advertisements or architectural designs that such display units be capable of being easily oriented in different directions. Again, the large size and weight of currently available units makes this difficult to achieve without complex support structures.
Another requirement for display systems for events, theatrical productions, advertisements or architectural designs is the need for the display to take up a minimal amount of storage space when stored and not in use. To meet this need, flexible substrate based displays have been created wherein the light emitting elements are incorporated into a fabric curtain as, for example, disclosed in U.S. Pat. No. 6,362,801 and U.S. Pat. No. 6,677,918. The fabric curtain compresses into a small space for storage. However, it is difficult to produce stable imagery with these curtain-based displays because the fabric or cloth backing both stretches and moves, thus changing the spatial relationship between the light emitting elements.
Another objective of these display units is the desire to create a controlled transparency of the unit. At some times it is desirable to see the display and the images shown on the display, while at other times it is desirable that the viewer be able to see through the display, so as to see scenery, performers, buildings, projection screens and the like that are located behind the display. One current solution to this problem involves constructing the display in a series of fixed vertical or horizontal straps, as disclosed in U.S. Pat. No. 5,900,850, with spaces between the display straps such that an appearance of transparency can be created by controlling the illumination levels of objects behind the display. When the objects behind are illuminated, they are visible through the gaps between the straps. When they are dark, they can not be seen. This method has the disadvantage that the display actually has a fixed transparency that can not be altered and that relies instead upon the human eye interpreting brightness levels as transparency. A further disadvantage of the system is that for the display to appear solid, the area behind has to be dark, thus making it difficult to for stage hands and performers to work behind the system or set up new scenery because they are never truly hidden from view. Further, these systems are large and suffer the same problems with respect to ease of installation and removal as described with respect to the solid units discussed above.
Attempts have been made to address these deficiencies by providing curtains or drapes that can be lowered or drawn behind the display strips to provide a completely opaque unit. This has the disadvantage that the curtain or drape is obvious to the audience as it is inserted or removed and further that it takes time to traverse the complete display, thus providing a “wipe” where the scene behind is revealed progressively from the display side rather then achieving an overall dissolve in transparency as is most desirable. In a further attempt to address some of these issues, displays have been created wherein the light emitting elements have been incorporated into a fabric curtain, as disclosed in U.S. Pat. No. 6,362,801 and U.S. Pat. No. 6,677,918, so as to provide a structure that is more easily constructed and removed. These displays are typically of low resolution and although they are easier to install and remove, they do not solve the controlled transparency issues. In addition, these displays have difficulty providing stable imagery due to the stretching and movement of cloth backing as described above. Thus, the systems are not suitable for permanent installations or as part of an architectural design or for advertising purposes.